As Winnipeggers hungry for history head out this weekend for Doors Open Winnipeg, a new smartphone app will offer a window into the city's past.

The annual Doors Open event gives people a chance to step inside buildings not always open to the public.

While they do that, a new app called On This Spot will also let them go on self-guided walking tours and compare buildings and places with historical photos of what they used to look like.

Currently, the app — which is free to download and available for Android and iOS phones — focuses on Winnipeg's Exchange District, which contains nearly 130 heritage buildings within 20 blocks.

"So it gives not only visitors, but Winnipeggers, a really sort of in-depth way to learn on their own time about our history in the Exchange — because the Exchange, as you know, is the most historic area for our built heritage in the city of Winnipeg," said Cindy Tugwell, executive director of Heritage Winnipeg, one of the driving forces behind the app.